Water for Davis Station
9 October 2006
Antarctica is the driest continent on the planet, and the provision of fresh water has remained a constant challenge for expeditioners since the formation of the Australian Antarctic programme in 1947.
Each station obtains its water supply through different means, ranging from reverse osmosis to melting blue ice, pumping from glacier streams and melt lakes. As it is back here, water is a necessity of life, not just for drinking, but for washing, cleaning and if required, for fire fighting.
At Davis, a reverse osmosis plant desalinates water from a small tarn behind the station. With greatly increased expeditioner numbers over the past few summers, the water level in the tarn has dropped significantly. Although the water level has increased slightly this season, the tarn has now reached a stage where it requires remediation, particularly with the planned increase of expeditioners after the introduction of intercontinental air transport next summer.
Water testing last summer indicated salinity in the tarn was 1.3 times higher than that of sea water. This coming summer, water will be pumped in from the sea to dilute the salt, and the first stage of installation of a containerised reverse osmosis unit will be undertaken. Capable of producing 100,000 litres a day, the current once weekly, two minute shower of today should become a thing of the past.
At present, water production of only 12,000 litres per day is a full time job over the summer for one plumber.
Requests for tender were called a few weeks ago for installation of the new, containerised reverse osmosis unit for the station. Tenders are now closed and under assessment.
With the new system, 10 mega litres of sea water will be pumped into the tarn just once at the beginning of the summer over a period of about a week, enough to last for the season. This will greatly reduce the workload and the associated energy costs, it will be sustainable in the long term and allow a plentiful supply of water for a large station population.
The containerised reverse osmosis unit is a major step in the overall station management strategy to cater for the introduction of the air link. Other developments include new summer accommodation to be built this 2006-07 summer and a new living quarters over the next few years.
Footings and a slab will be laid this summer next to the tarn building to accommodate the containerised unit, which is expected to be operational during the 2007-08 summer.